The disk is full
What it looks like in your log
java.io.IOException: No space left on device
What causes it
There is no free space left to save the world or write logs.
How to fix it
Free up disk space on this computer and start the server again.
Why it happens
The volume the server writes to has no free space. Every save fails, every log line is dropped, and chunks that were mid-write when the disk filled are now truncated, which is how disk-full turns into corrupted regions a day later. Logs, crash reports, on-server backups and player-generated chunks are the usual causes; a modpack that generates 30 GB of world in a week is not unusual.
Fix it step by step
- 1Free space immediatelyDelete old logs from logs/, old crash reports from crash-reports/, and any backup archives stored on the same disk. Those alone often recover gigabytes.
- 2Move backups off the diskBackups on the same volume as the world are both the cause of the full disk and useless when the disk dies. Send them elsewhere.
- 3Check for a runawayA log file growing by gigabytes an hour is a plugin or mod spamming errors. Fix the spam; the log is a symptom.
- 4Verify the worldAfter the disk filled, check the log for region file errors on the next start. The chunk corruption page covers repair.
- 5Get more disk, or trim the worldIf the world is simply large, prune chunks nobody has visited with a tool such as MCA Selector, or move to a plan with the space.
If that didn't work
If df shows free space and the error persists, the filesystem ran out of inodes, or a quota applies to the server's user. Both look identical to Java.
Not sure this is your problem? Paste your log and Roastd will tell you which of these it actually matched, and what else it found.
Check your own log